Access Queries

1. Access Queries Office 2013/365

2. Queries • Most common type of Query is selection(projection) • Specify sources for data retrieval • table(s) and/or query(ies) • Specify attributes(fields) to be retrieved • Selection criteria • Calculations that need to be performed • Action Queries • Other types such as crosstabs

3. Query Creation • Structured Query Language (SQL) • The user enters commands according to a pre-defined syntax to retrieve desired data. • Query By Example (QBE) • The user starts with a sample of the table(s) columns and marks the fields he or she wants to include in the answer. • Defaults are available for summarizing and manipulating the data.

4. Creating Queries • Query Wizard • QBE Query Design • The user starts with a sample of the table(s) columns and marks the fields he or she wants to include in the answer. • Defaults are available for summarizing and manipulating the data. • SQL design (beyond scope of our class) • The user enters commands according to a pre-defined syntax to retrieve desired data.

5. Creating Query • Wizards • Click on create tab • Select query wizard • Select simple query • Select your data source(s) • Select desired attributes from each data source • Select next • Name query • Click on finish • Limitation • May be able to do a summary calculation, but not a calculated field

6. Wizard Click on create tab and select Query Wizard

7. Click on Simple Query wizard

8. Select data sources and desired attributes from each source

9. Name your query

10. Resulting Dynaset

11. Access creates the SQL needed to do the query for the wizard • SQL for previous query example SELECT Customers.[ID], Customers.[Last Name], Customers.[First Name], Customers.[E-mail Address], Customers.[Job Title], Customers.[Business Phone] FROM Customers;

12. Design View • Uses QBE (what we will use) • Design View • Click on create tab • Select query design • Select your data sources and click on add • Select attributes from each data source and drag to grid below • Run query • Save query if it will be used on a regular basis • Can create calculated fields

13. Click on create tab and select Query Design

14. Select your data sources and click on add

15. Select attributes from each data source and double click or drag to grid below

16. Select design tab and Click on Run symbol to execute query

17. Resulting Dynaset SQL SELECT Customers.[ID], Customers.[Last Name], Customers.[First Name], Customers.[E-mail Address], Customers.[Job Title], Customers.[Business Phone] FROM Customers;

18. Examples to follow based on this database

19. Customer table data

20. Queries with selection criteria • Use design view when using selection criteria • Select your data sources and attributes of interest from your data sources enter selection criteria • Run query

21. Query to list Customers from CA Selection Criteria

22. Resulting Dynaset SQL SELECT Customers.ID, Customers.Company, Customers.City, Customers.[State/Province] FROM Customers WHERE (((Customers.[State/Province])="CA"));

23. Comparison operators <, >, =, <=, >=, and <> Not equal to Logical operators And, Or, and Not Queries(complex selection criteria)

24. Multiple Criteria • AND operator • Queries that must satisfy more than one condition, with all conditions being true, use the ANDoperator • OR operator • When any one of several criteria is all that is required for a row to be displayed in a dynaset, then you use the OR operator

25. And Operator Selection Criteria

26. Resulting Dynaset SQL SELECT Customers.ID, Customers.Company, Customers.City FROM Customers WHERE (((Customers.City)="Los Angelas") AND ((Customers.[State/Province])="CA"));

27. OR Operator Selection Criteria

28. Resulting Dynaset SQL SELECT Customers.ID, Customers.Company, Customers.City FROM Customers WHERE (((Customers.[State/Province])="CA")) OR (((Customers.[State/Province])="UT"));

29. Action queries • Action Queries • Make table • Append • update • Delete • Action queries alter information as opposed to selection queries, which passively display information without altering anything • Back up data before performing action queries • No undo

30. Action Queries • Make Table • Query selects records from data base and saves the records in a new table • Append • Make query add records to an existing table • Update • Make query update data in an existing table • Delete • Make the query delete the information from an existing table where the data matches the criteria

31. Action Queries • Use design view to perform action queries • Select create tab • Query design • Select data source(s) • Select data and/or selection criteria • Select design, select action query • Save query • Run query • You will get a pop-up message indicating what the query is about to do

32. Make table, Append, Update, Delete Depending on action query selected you need to specify fields and/or criteria

33. Example Action query message

34. Example Action query message

35. Append Query Considerations • Select the table containing the data you want to add • Source may be internal or external • Select the destination • Fields must be of like data type • Field mapping

36. Destination Source

37. Note: Access has attempting to map the fields from tblCA to table customer Access maps all fields between the two tables with the same field names

38. Note: Since the two tables used a different names for this field, manual mapping required